mirror of
https://github.com/winfsp/winfsp.git
synced 2025-10-29 19:18:39 -05:00
sys: IRP_MJ_CREATE: refactoring to support Overwrite
This commit is contained in:
Bill Zissimopoulos
@@ -46,6 +46,7 @@ enum
|
||||
{
|
||||
FspFsctlTransactUnknownKind = 0,
|
||||
FspFsctlTransactCreateKind,
|
||||
FspFsctlTransactCreate2Kind,
|
||||
FspFsctlTransactCleanupKind,
|
||||
FspFsctlTransactCloseKind,
|
||||
FspFsctlTransactReadKind,
|
||||
@@ -123,12 +124,20 @@ typedef struct
|
||||
{
|
||||
UINT64 UserContext;
|
||||
UINT64 UserContext2;
|
||||
UINT32 ReadAccess:1; /* file was open for read access */
|
||||
UINT32 WriteAccess:1; /* file was open for write access */
|
||||
UINT32 DeleteAccess:1; /* file was open for delete access */
|
||||
UINT32 SharedRead:1; /* file was open for shared read access */
|
||||
UINT32 SharedWrite:1; /* file was open for shared write access */
|
||||
UINT32 SharedDelete:1; /* file was open for shared delete access */
|
||||
UINT32 CloseStatus; /* if non-0 close the file (and do NOT overwrite!) */
|
||||
UINT32 FileAttributes; /* FILE_ATTRIBUTE_{NORMAL,DIRECTORY,etc.} */
|
||||
UINT32 Supersede:1; /* 0: FILE_OVERWRITE operation, 1: FILE_SUPERSEDE operation */
|
||||
} Create2;
|
||||
struct
|
||||
{
|
||||
UINT64 UserContext;
|
||||
UINT64 UserContext2;
|
||||
UINT32 ReadAccess:1; /* file was open for read access */
|
||||
UINT32 WriteAccess:1; /* file was open for write access */
|
||||
UINT32 DeleteAccess:1; /* file was open for delete access */
|
||||
UINT32 SharedRead:1; /* file was open for shared read access */
|
||||
UINT32 SharedWrite:1; /* file was open for shared write access */
|
||||
UINT32 SharedDelete:1; /* file was open for shared delete access */
|
||||
} Cleanup;
|
||||
struct
|
||||
{
|
||||
@@ -169,6 +178,13 @@ typedef struct
|
||||
FSP_FSCTL_TRANSACT_BUF FileName; /* file name to use for STATUS_REPARSE */
|
||||
} Reparse;
|
||||
} Create;
|
||||
struct
|
||||
{
|
||||
UINT64 UserContext; /* open file user context (unique file id) */
|
||||
UINT64 UserContext2; /* kernel file object user context (only low 32 bits valid) */
|
||||
UINT64 AllocationSize; /* file allocation size */
|
||||
UINT64 FileSize; /* file size */
|
||||
} Create2;
|
||||
} Rsp;
|
||||
FSP_FSCTL_DECLSPEC_ALIGN UINT8 Buffer[];
|
||||
} FSP_FSCTL_TRANSACT_RSP;
|
||||
|
||||
@@ -60,19 +60,8 @@ static NTSTATUS FspFsvolCleanup(
|
||||
UINT64 UserContext = FsContext->UserContext;
|
||||
UINT64 UserContext2 = (UINT_PTR)FileObject->FsContext2;
|
||||
FSP_FSCTL_TRANSACT_REQ *Request;
|
||||
LONG OpenCount;
|
||||
|
||||
/* all handles on this FileObject are gone; close the FileObject */
|
||||
OpenCount = FspFileContextClose(FsContext);
|
||||
|
||||
/* is the FsContext going away as well? */
|
||||
if (0 == OpenCount)
|
||||
{
|
||||
/* remove the FsContext from the volume device generic table */
|
||||
FspFsvolDeviceLockContextTable(FsvolDeviceObject);
|
||||
FspFsvolDeviceDeleteContext(FsvolDeviceObject, FsContext->UserContext, 0);
|
||||
FspFsvolDeviceUnlockContextTable(FsvolDeviceObject);
|
||||
}
|
||||
FspFileContextClose(FsvolDeviceObject, FsContext);
|
||||
|
||||
/* create the user-mode file system request; MustSucceed because IRP_MJ_CLEANUP cannot fail */
|
||||
FspIopCreateRequestMustSucceed(Irp, FileNameRequired ? &FsContext->FileName : 0, 0, &Request);
|
||||
|
||||
327
src/sys/create.c
327
src/sys/create.c
@@ -292,27 +292,72 @@ NTSTATUS FspFsvolCreatePrepare(
|
||||
PAGED_CODE();
|
||||
|
||||
NTSTATUS Result;
|
||||
BOOLEAN Success;
|
||||
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
|
||||
PACCESS_STATE AccessState = IrpSp->Parameters.Create.SecurityContext->AccessState;
|
||||
PACCESS_STATE AccessState;
|
||||
HANDLE UserModeAccessToken;
|
||||
PEPROCESS Process;
|
||||
FSP_FILE_CONTEXT *FsContext;
|
||||
|
||||
/* get a user-mode handle to the access token */
|
||||
Result = ObOpenObjectByPointer(SeQuerySubjectContextToken(&AccessState->SubjectSecurityContext),
|
||||
0, 0, TOKEN_QUERY, *SeTokenObjectType, UserMode, &UserModeAccessToken);
|
||||
if (!NT_SUCCESS(Result))
|
||||
return Result;
|
||||
if (FspFsctlTransactCreateKind == Request->Kind)
|
||||
{
|
||||
AccessState = IrpSp->Parameters.Create.SecurityContext->AccessState;
|
||||
|
||||
/* get a pointer to the current process so that we can close the access token later */
|
||||
Process = PsGetCurrentProcess();
|
||||
ObReferenceObject(Process);
|
||||
/* get a user-mode handle to the access token */
|
||||
Result = ObOpenObjectByPointer(SeQuerySubjectContextToken(&AccessState->SubjectSecurityContext),
|
||||
0, 0, TOKEN_QUERY, *SeTokenObjectType, UserMode, &UserModeAccessToken);
|
||||
if (!NT_SUCCESS(Result))
|
||||
return Result;
|
||||
|
||||
/* send the user-mode handle to the user-mode file system */
|
||||
FspIopRequestContext(Request, RequestAccessToken) = UserModeAccessToken;
|
||||
FspIopRequestContext(Request, RequestProcess) = Process;
|
||||
Request->Req.Create.AccessToken = (UINT_PTR)UserModeAccessToken;
|
||||
/* get a pointer to the current process so that we can close the access token later */
|
||||
Process = PsGetCurrentProcess();
|
||||
ObReferenceObject(Process);
|
||||
|
||||
return STATUS_SUCCESS;
|
||||
/* send the user-mode handle to the user-mode file system */
|
||||
FspIopRequestContext(Request, RequestAccessToken) = UserModeAccessToken;
|
||||
FspIopRequestContext(Request, RequestProcess) = Process;
|
||||
Request->Req.Create.AccessToken = (UINT_PTR)UserModeAccessToken;
|
||||
|
||||
return STATUS_SUCCESS;
|
||||
}
|
||||
else if (FspFsctlTransactCreate2Kind == Request->Kind)
|
||||
{
|
||||
FsContext = FspIopRequestContext(Request, RequestFsContext);
|
||||
|
||||
/* lock the FsContext for Paging IO */
|
||||
Success = FspFileContextPgioLockExclusive(FsContext, FALSE);
|
||||
if (!Success)
|
||||
{
|
||||
/* repost the IRP to retry later */
|
||||
FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension =
|
||||
FspFsvolDeviceExtension(IrpSp->DeviceObject);
|
||||
if (FspIoqPostIrpNoCap(FsvolDeviceExtension->Ioq, Irp, &Result))
|
||||
Result = STATUS_PENDING;
|
||||
return Result;
|
||||
}
|
||||
|
||||
/* see what the MM thinks about all this */
|
||||
LARGE_INTEGER Zero = { 0 };
|
||||
Success = MmCanFileBeTruncated(&FsContext->NonPaged->SectionObjectPointers, &Zero);
|
||||
if (!Success)
|
||||
{
|
||||
/* cannot truncate; tell user mode that we are closing the file */
|
||||
FspFileContextPgioUnlock(FsContext);
|
||||
Request->Req.Create2.CloseStatus = (UINT32)STATUS_USER_MAPPED_FILE;
|
||||
return STATUS_SUCCESS;
|
||||
}
|
||||
|
||||
/* purge any caches on this file */
|
||||
CcPurgeCacheSection(&FsContext->NonPaged->SectionObjectPointers, 0, 0, FALSE);
|
||||
|
||||
return STATUS_SUCCESS;
|
||||
}
|
||||
else
|
||||
{
|
||||
ASSERT(0);
|
||||
|
||||
return STATUS_INVALID_PARAMETER;
|
||||
}
|
||||
}
|
||||
|
||||
VOID FspFsvolCreateComplete(
|
||||
@@ -325,121 +370,181 @@ VOID FspFsvolCreateComplete(
|
||||
PFILE_OBJECT FileObject = IrpSp->FileObject;
|
||||
SHARE_ACCESS TemporaryShareAccess;
|
||||
UNICODE_STRING ReparseFileName;
|
||||
FSP_FSCTL_TRANSACT_REQ *Request;
|
||||
FSP_FILE_CONTEXT *FsContext;
|
||||
BOOLEAN Inserted;
|
||||
FSP_FSCTL_TRANSACT_REQ *Request = FspIrpRequest(Irp);
|
||||
FSP_FILE_CONTEXT *FsContext = FspIopRequestContext(Request, RequestFsContext);
|
||||
|
||||
/* did the user-mode file system sent us a failure code? */
|
||||
if (!NT_SUCCESS(Response->IoStatus.Status))
|
||||
if (FspFsctlTransactCreateKind == Request->Kind)
|
||||
{
|
||||
Irp->IoStatus.Information = (ULONG_PTR)Response->IoStatus.Information;
|
||||
Result = Response->IoStatus.Status;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* special case STATUS_REPARSE */
|
||||
if (STATUS_REPARSE == Result)
|
||||
{
|
||||
ReparseFileName.Buffer =
|
||||
(PVOID)(Response->Buffer + Response->Rsp.Create.Reparse.FileName.Offset);
|
||||
ReparseFileName.Length = ReparseFileName.MaximumLength =
|
||||
Response->Rsp.Create.Reparse.FileName.Size;
|
||||
|
||||
Result = STATUS_ACCESS_DENIED;
|
||||
if (IO_REPARSE == Response->IoStatus.Information)
|
||||
/* did the user-mode file system sent us a failure code? */
|
||||
if (!NT_SUCCESS(Response->IoStatus.Status))
|
||||
{
|
||||
if (0 == ReparseFileName.Length ||
|
||||
(PUINT8)ReparseFileName.Buffer + ReparseFileName.Length >
|
||||
(PUINT8)Response + Response->Size)
|
||||
Irp->IoStatus.Information = 0;
|
||||
Result = Response->IoStatus.Status;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* special case STATUS_REPARSE */
|
||||
if (STATUS_REPARSE == Result)
|
||||
{
|
||||
ReparseFileName.Buffer =
|
||||
(PVOID)(Response->Buffer + Response->Rsp.Create.Reparse.FileName.Offset);
|
||||
ReparseFileName.Length = ReparseFileName.MaximumLength =
|
||||
Response->Rsp.Create.Reparse.FileName.Size;
|
||||
|
||||
Result = STATUS_ACCESS_DENIED;
|
||||
if (IO_REPARSE == Response->IoStatus.Information)
|
||||
{
|
||||
if (0 == ReparseFileName.Length ||
|
||||
(PUINT8)ReparseFileName.Buffer + ReparseFileName.Length >
|
||||
(PUINT8)Response + Response->Size)
|
||||
FSP_RETURN();
|
||||
|
||||
if (ReparseFileName.Length > FileObject->FileName.MaximumLength)
|
||||
{
|
||||
PVOID Buffer = FspAllocExternal(ReparseFileName.Length);
|
||||
if (0 == Buffer)
|
||||
FSP_RETURN(Result = STATUS_INSUFFICIENT_RESOURCES);
|
||||
FspFreeExternal(FileObject->FileName.Buffer);
|
||||
FileObject->FileName.MaximumLength = ReparseFileName.Length;
|
||||
FileObject->FileName.Buffer = Buffer;
|
||||
}
|
||||
FileObject->FileName.Length = 0;
|
||||
RtlCopyUnicodeString(&FileObject->FileName, &ReparseFileName);
|
||||
|
||||
/*
|
||||
* The RelatedFileObject does not need to be changed according to:
|
||||
* https://support.microsoft.com/en-us/kb/319447
|
||||
*
|
||||
* Quote:
|
||||
* The fact that the first create-file operation is performed
|
||||
* relative to another file object does not matter. Do not modify
|
||||
* the RelatedFileObject field of the FILE_OBJECT. To perform the
|
||||
* reparse operation, the IO Manager considers only the FileName
|
||||
* field and not the RelatedFileObject. Additionally, the IO Manager
|
||||
* frees the RelatedFileObject, as appropriate, when it handles the
|
||||
* STATUS_REPARSE status returned by the filter. Therefore, it is not
|
||||
* the responsibility of the filter to free that file object.
|
||||
*/
|
||||
}
|
||||
else
|
||||
if (IO_REMOUNT == Response->IoStatus.Information)
|
||||
{
|
||||
if (0 != ReparseFileName.Length)
|
||||
FSP_RETURN();
|
||||
}
|
||||
else
|
||||
FSP_RETURN();
|
||||
|
||||
if (ReparseFileName.Length > FileObject->FileName.MaximumLength)
|
||||
{
|
||||
PVOID Buffer = FspAllocExternal(ReparseFileName.Length);
|
||||
if (0 == Buffer)
|
||||
FSP_RETURN(Result = STATUS_INSUFFICIENT_RESOURCES);
|
||||
FspFreeExternal(FileObject->FileName.Buffer);
|
||||
FileObject->FileName.MaximumLength = ReparseFileName.Length;
|
||||
FileObject->FileName.Buffer = Buffer;
|
||||
}
|
||||
FileObject->FileName.Length = 0;
|
||||
RtlCopyUnicodeString(&FileObject->FileName, &ReparseFileName);
|
||||
Irp->IoStatus.Information = (ULONG_PTR)Response->IoStatus.Information;
|
||||
Result = Response->IoStatus.Status;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* get the FsContext from our Request and associate it with the Response UserContext */
|
||||
FsContext->Header.AllocationSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
FsContext->Header.FileSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
FsContext->UserContext = Response->Rsp.Create.Opened.UserContext;
|
||||
|
||||
/* open the FsContext */
|
||||
FspIopRequestContext(Request, RequestFsContext) =
|
||||
FspFileContextOpen(FsvolDeviceObject, FsContext);
|
||||
|
||||
/* set up share access on FileObject; user-mode file system assumed to have done share check */
|
||||
IoSetShareAccess(Response->Rsp.Create.Opened.GrantedAccess, IrpSp->Parameters.Create.ShareAccess,
|
||||
FileObject, &TemporaryShareAccess);
|
||||
|
||||
/* finish setting up the FileObject */
|
||||
if (0 != FsvolDeviceExtension->FsvrtDeviceObject)
|
||||
FileObject->Vpb = FsvolDeviceExtension->FsvrtDeviceObject->Vpb;
|
||||
FileObject->SectionObjectPointer = &FsContext->NonPaged->SectionObjectPointers;
|
||||
FileObject->PrivateCacheMap = 0;
|
||||
FileObject->FsContext = FsContext;
|
||||
FileObject->FsContext2 = (PVOID)(UINT_PTR)Response->Rsp.Create.Opened.UserContext2;
|
||||
|
||||
if (FILE_SUPERSEDED == Response->IoStatus.Information ||
|
||||
FILE_OVERWRITTEN == Response->IoStatus.Information)
|
||||
{
|
||||
/*
|
||||
* Oh, noes! We have to go back to user mode to overwrite the file!
|
||||
*/
|
||||
|
||||
/* delete the old request */
|
||||
FspIopRequestContext(Request, RequestFsContext) = 0;
|
||||
FspIrpRequest(Irp) = 0;
|
||||
FspIopDeleteRequest(Request);
|
||||
|
||||
/* create the Create2 request; MustSucceed because we must either overwrite or close */
|
||||
FspIopCreateRequestMustSucceed(Irp,
|
||||
FsvolDeviceExtension->VolumeParams.FileNameRequired ? &FsContext->FileName : 0, 0,
|
||||
&Request);
|
||||
|
||||
/* associate the FsContext with the Create2 request */
|
||||
FspIopRequestContext(Request, RequestFsContext) = FsContext;
|
||||
|
||||
/* populate the Create2 request */
|
||||
Request->Kind = FspFsctlTransactCreate2Kind;
|
||||
Request->Req.Create2.UserContext = FsContext->UserContext;
|
||||
Request->Req.Create2.UserContext2 = (UINT_PTR)FileObject->FsContext2;
|
||||
Request->Req.Create2.FileAttributes = IrpSp->Parameters.Create.FileAttributes;
|
||||
Request->Req.Create2.Supersede = FILE_SUPERSEDED == Response->IoStatus.Information;
|
||||
Request->Req.Create2.CloseStatus = STATUS_SUCCESS;
|
||||
|
||||
/*
|
||||
* The RelatedFileObject does not need to be changed according to:
|
||||
* https://support.microsoft.com/en-us/kb/319447
|
||||
*
|
||||
* Quote:
|
||||
* The fact that the first create-file operation is performed
|
||||
* relative to another file object does not matter. Do not modify
|
||||
* the RelatedFileObject field of the FILE_OBJECT. To perform the
|
||||
* reparse operation, the IO Manager considers only the FileName
|
||||
* field and not the RelatedFileObject. Additionally, the IO Manager
|
||||
* frees the RelatedFileObject, as appropriate, when it handles the
|
||||
* STATUS_REPARSE status returned by the filter. Therefore, it is not
|
||||
* the responsibility of the filter to free that file object.
|
||||
* Note that it is still possible for this request to not be delivered,
|
||||
* if the volume device Ioq is stopped. But such failures are benign
|
||||
* from our perspective, because they mean that the file system is going
|
||||
* away and should correctly tear things down.
|
||||
*/
|
||||
|
||||
if (FspIoqPostIrpNoCap(FsvolDeviceExtension->Ioq, Irp, &Result))
|
||||
Result = STATUS_PENDING;
|
||||
}
|
||||
else
|
||||
if (IO_REMOUNT == Response->IoStatus.Information)
|
||||
{
|
||||
if (0 != ReparseFileName.Length)
|
||||
FSP_RETURN();
|
||||
/* SUCCESS! */
|
||||
Irp->IoStatus.Information = (ULONG_PTR)Response->IoStatus.Information;
|
||||
Result = STATUS_SUCCESS;
|
||||
}
|
||||
else
|
||||
FSP_RETURN();
|
||||
|
||||
Irp->IoStatus.Information = (ULONG_PTR)Response->IoStatus.Information;
|
||||
Result = Response->IoStatus.Status;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* get the FsContext from our Request and associate it with the Response UserContext */
|
||||
Request = FspIrpRequest(Irp);
|
||||
FsContext = FspIopRequestContext(Request, RequestFsContext);
|
||||
FsContext->Header.AllocationSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
FsContext->Header.FileSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
FsContext->UserContext = Response->Rsp.Create.Opened.UserContext;
|
||||
|
||||
/*
|
||||
* Attempt to insert our FsContext into the volume device's generic table.
|
||||
* If an FsContext with the same UserContext already exists, then use that
|
||||
* FsContext instead.
|
||||
*/
|
||||
FspFsvolDeviceLockContextTable(FsvolDeviceObject);
|
||||
FsContext = FspFsvolDeviceInsertContext(FsvolDeviceObject,
|
||||
FsContext->UserContext, FsContext, &FsContext->ElementStorage, &Inserted);
|
||||
ASSERT(0 != FsContext);
|
||||
if (Inserted)
|
||||
/* Our FsContext was inserted into the volume device's generic table.
|
||||
* Disassociate it from the Request.
|
||||
*/
|
||||
FspIopRequestContext(Request, RequestFsContext) = 0;
|
||||
else
|
||||
else if (FspFsctlTransactCreate2Kind == Request->Kind)
|
||||
{
|
||||
/*
|
||||
* We are using a previously inserted FsContext. We must retain it.
|
||||
* Our own FsContext is still associated with the Request and will be
|
||||
* deleted during IRP completion.
|
||||
* A Create2 request will either succeed or else fail and close the corresponding file.
|
||||
* There is no need to reach out to user-mode again and ask them to close the file.
|
||||
*/
|
||||
FspFileContextRetain(FsContext);
|
||||
FspFileContextOpen(FsContext);
|
||||
FspFsvolDeviceUnlockContextTable(FsvolDeviceObject);
|
||||
|
||||
/* set up share access on FileObject; user-mode file system assumed to have done share check */
|
||||
IoSetShareAccess(Response->Rsp.Create.Opened.GrantedAccess, IrpSp->Parameters.Create.ShareAccess,
|
||||
FileObject, &TemporaryShareAccess);
|
||||
/* was this a close request? */
|
||||
if (STATUS_SUCCESS != Request->Req.Create2.CloseStatus)
|
||||
{
|
||||
Irp->IoStatus.Information = 0;
|
||||
Result = STATUS_SUCCESS != Request->Req.Create2.CloseStatus;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* finish seting up the FileObject */
|
||||
if (0 != FsvolDeviceExtension->FsvrtDeviceObject)
|
||||
FileObject->Vpb = FsvolDeviceExtension->FsvrtDeviceObject->Vpb;
|
||||
FileObject->SectionObjectPointer = &FsContext->NonPaged->SectionObjectPointers;
|
||||
FileObject->PrivateCacheMap = 0;
|
||||
FileObject->FsContext = FsContext;
|
||||
FileObject->FsContext2 = (PVOID)(UINT_PTR)Response->Rsp.Create.Opened.UserContext2;
|
||||
/* did the user-mode file system sent us a failure code? */
|
||||
if (!NT_SUCCESS(Response->IoStatus.Status))
|
||||
{
|
||||
FspFileContextPgioUnlock(FsContext);
|
||||
FspFileContextClose(FsvolDeviceObject, FsContext);
|
||||
|
||||
/* SUCCESS! */
|
||||
Irp->IoStatus.Information = (ULONG_PTR)Response->IoStatus.Information;
|
||||
Result = Response->IoStatus.Status;
|
||||
Irp->IoStatus.Information = 0;
|
||||
Result = Response->IoStatus.Status;
|
||||
FSP_RETURN();
|
||||
}
|
||||
|
||||
/* file was successfully overwritten/superseded */
|
||||
FsContext->Header.AllocationSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
FsContext->Header.FileSize.QuadPart = Response->Rsp.Create.Opened.AllocationSize;
|
||||
CcSetFileSizes(FileObject, (PCC_FILE_SIZES)&FsContext->Header.AllocationSize);
|
||||
|
||||
FspFileContextPgioUnlock(FsContext);
|
||||
|
||||
/* SUCCESS! */
|
||||
Irp->IoStatus.Information = Request->Req.Create2.Supersede ? FILE_SUPERSEDED : FILE_OVERWRITTEN;
|
||||
Result = STATUS_SUCCESS;
|
||||
}
|
||||
else
|
||||
ASSERT(0);
|
||||
|
||||
FSP_LEAVE_IOC(
|
||||
"FileObject=%p[%p:\"%wZ\"]",
|
||||
|
||||
@@ -527,12 +527,21 @@ typedef struct
|
||||
NTSTATUS FspFileContextCreate(PDEVICE_OBJECT DeviceObject,
|
||||
ULONG ExtraSize, FSP_FILE_CONTEXT **PFsContext);
|
||||
VOID FspFileContextDelete(FSP_FILE_CONTEXT *FsContext);
|
||||
FSP_FILE_CONTEXT *FspFileContextOpen(PDEVICE_OBJECT FsvolDeviceObject,
|
||||
FSP_FILE_CONTEXT *FsContext);
|
||||
VOID FspFileContextClose(PDEVICE_OBJECT FsvolDeviceObject,
|
||||
FSP_FILE_CONTEXT *FsContext);
|
||||
static inline
|
||||
VOID FspFileContextRetain(FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
InterlockedIncrement(&FsContext->RefCount);
|
||||
}
|
||||
static inline
|
||||
VOID FspFileContextRetain2(FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
InterlockedAdd(&FsContext->RefCount, 2);
|
||||
}
|
||||
static inline
|
||||
VOID FspFileContextRelease(FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
LONG RefCount = InterlockedDecrement(&FsContext->RefCount);
|
||||
@@ -540,14 +549,34 @@ VOID FspFileContextRelease(FSP_FILE_CONTEXT *FsContext)
|
||||
FspFileContextDelete(FsContext);
|
||||
}
|
||||
static inline
|
||||
VOID FspFileContextOpen(FSP_FILE_CONTEXT *FsContext)
|
||||
BOOLEAN FspFileContextLockShared(FSP_FILE_CONTEXT *FsContext, BOOLEAN Wait)
|
||||
{
|
||||
InterlockedIncrement(&FsContext->OpenCount);
|
||||
return ExAcquireResourceSharedLite(FsContext->Header.Resource, Wait);
|
||||
}
|
||||
static inline
|
||||
LONG FspFileContextClose(FSP_FILE_CONTEXT *FsContext)
|
||||
BOOLEAN FspFileContextLockExclusive(FSP_FILE_CONTEXT *FsContext, BOOLEAN Wait)
|
||||
{
|
||||
return InterlockedDecrement(&FsContext->OpenCount);
|
||||
return ExAcquireResourceExclusiveLite(FsContext->Header.Resource, Wait);
|
||||
}
|
||||
static inline
|
||||
VOID FspFileContextUnlock(FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
ExReleaseResourceLite(FsContext->Header.Resource);
|
||||
}
|
||||
static inline
|
||||
BOOLEAN FspFileContextPgioLockShared(FSP_FILE_CONTEXT *FsContext, BOOLEAN Wait)
|
||||
{
|
||||
return ExAcquireResourceSharedLite(FsContext->Header.PagingIoResource, Wait);
|
||||
}
|
||||
static inline
|
||||
BOOLEAN FspFileContextPgioLockExclusive(FSP_FILE_CONTEXT *FsContext, BOOLEAN Wait)
|
||||
{
|
||||
return ExAcquireResourceExclusiveLite(FsContext->Header.PagingIoResource, Wait);
|
||||
}
|
||||
static inline
|
||||
VOID FspFileContextPgioUnlock(FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
ExReleaseResourceLite(FsContext->Header.PagingIoResource);
|
||||
}
|
||||
|
||||
/* debug */
|
||||
|
||||
@@ -72,3 +72,74 @@ VOID FspFileContextDelete(FSP_FILE_CONTEXT *FsContext)
|
||||
|
||||
FspFree(FsContext);
|
||||
}
|
||||
|
||||
FSP_FILE_CONTEXT *FspFileContextOpen(PDEVICE_OBJECT FsvolDeviceObject,
|
||||
FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
/*
|
||||
* Attempt to insert our FsContext into the volume device's generic table.
|
||||
* If an FsContext with the same UserContext already exists, then use that
|
||||
* FsContext instead.
|
||||
*/
|
||||
|
||||
FSP_FILE_CONTEXT *OpenedFsContext;
|
||||
BOOLEAN Inserted;
|
||||
|
||||
FspFsvolDeviceLockContextTable(FsvolDeviceObject);
|
||||
|
||||
OpenedFsContext = FspFsvolDeviceInsertContext(FsvolDeviceObject,
|
||||
FsContext->UserContext, FsContext, &FsContext->ElementStorage, &Inserted);
|
||||
ASSERT(0 != OpenedFsContext);
|
||||
|
||||
if (Inserted)
|
||||
{
|
||||
/*
|
||||
* The new FsContext was inserted into the Context table.
|
||||
* Retain it. There should be (at least) two references to this FsContext,
|
||||
* one from our caller and one from the Context table.
|
||||
*/
|
||||
ASSERT(OpenedFsContext == FsContext);
|
||||
|
||||
FspFileContextRetain(OpenedFsContext);
|
||||
}
|
||||
else
|
||||
{
|
||||
/*
|
||||
* The new FsContext was NOT inserted into the Context table,
|
||||
* instead a prior FsContext is being opened.
|
||||
* Release the new FsContext since the caller will no longer reference it,
|
||||
* and retain the prior FsContext TWICE, once for our caller and once for
|
||||
* the Context table.
|
||||
*/
|
||||
ASSERT(OpenedFsContext != FsContext);
|
||||
|
||||
FspFileContextRetain2(OpenedFsContext);
|
||||
}
|
||||
|
||||
InterlockedIncrement(&OpenedFsContext->OpenCount);
|
||||
|
||||
FspFsvolDeviceUnlockContextTable(FsvolDeviceObject);
|
||||
|
||||
if (!Inserted)
|
||||
FspFileContextRelease(FsContext);
|
||||
|
||||
return OpenedFsContext;
|
||||
}
|
||||
|
||||
VOID FspFileContextClose(PDEVICE_OBJECT FsvolDeviceObject,
|
||||
FSP_FILE_CONTEXT *FsContext)
|
||||
{
|
||||
/*
|
||||
* Close the FsContext. If the OpenCount becomes zero remove it
|
||||
* from the Context table.
|
||||
*/
|
||||
|
||||
if (0 == InterlockedDecrement(&FsContext->OpenCount))
|
||||
{
|
||||
FspFsvolDeviceLockContextTable(FsvolDeviceObject);
|
||||
FspFsvolDeviceDeleteContext(FsvolDeviceObject, FsContext->UserContext, 0);
|
||||
FspFsvolDeviceUnlockContextTable(FsvolDeviceObject);
|
||||
}
|
||||
|
||||
FspFileContextRelease(FsContext);
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user